The key to strategic planning is understanding what it is. It is a plan. A blueprint for what to do given what you know. It is not a combination for a padlock. Unlike a padlock, you don't know if it's going to be many turns to the right, two to the left and then one to the right. It could be any which way and there might be numbers you didn't account for.

Strategic plans that say, "should the enemy do X or Y, we'll do A or B" are of the better variety. This respects that the future is unknown. Strategic plans that say, "in Q1, we'll do A; in Q2, we'll do B; in Q3, we'll do C; and, in Q4, we'll do D" are fine only in the sense of knowing what the future will be. Most organizations and people don't have this degree of certainty in their lives.

Should you find yourself in an organization (business, marriage, detente) whose future is unclear, but whose plans seem so, try to find out what happens if the conditions change. Ask if, in all instances, this is what we'll do, no matter what. If your organization still wants to hold to plan despite future uncertainties, you'll be rewarded if you guessed right...